Cytotoxic activity of peripheral mononuclear cells in normal pregnancy

Killer-cell activity was studied in healthy pregnants in all three trimesters of pregnancy. Results were compared with values obtained three months after delivery, as well as with similar data of non-pregnant women. The effect of pregnant and non-pregnant sera on cytotoxic activity has also been investigated. Killer-cell activity was measured by a capacity test on antibody coated human red blood cells. According to the results, healthy pregnancy did not influence the maternal killer-cell activity. On the other hand, the various sera had a decreasing effect on the killer-cell activity of both pregnant and non-pregnant women. Attention is called to the aspecific inhibitory effect of sera.